This invention relates to a chair which because of its characteristics and construction, as will be described, facilitates use by weakened, partially disabled, or infirm users suffering a variety of ailments in a manner constituting a distinct improvement over patient-type chairs of the prior art. Because of the comforts it provides, the chair of the invention also is appropriate for the seating needs of healthy users, and it is also a distinct improvement over chairs of the prior art for general seating use.
An important feature of this chair is its ability to provide a defined motion pattern in response to the body pressure of the user, such that the motion constitutes a controlled pattern and a relaxing sensation for the user.
There are many chair configurations which have found use in the hospital room, nursing home, extended care facility, sick room at home or as loungers for general use. No chair now available has the desirable motion characteristics of the chair described herein.
A major drawback of presently available chairs is the widespread problem of weakened users being unable to get out of the usual easy, or lounge, chairs by themselves because they haven't the strength to do so in the particular groups of muscles called into play by the configuration of the chair they were trying to get out of (typically the arm and upper body muscles). The problem is compounded by the relatively widespread incidence of back problems common among nurses and aides because of their having through their shift to help patients or wards out of chairs and into standing positions. One object of the invention is to provide a chair which enables the user to utilize his strongest muscles (usually leg muscles) for rising up out of the chair, by providing, in effect, a catapulting motion to the user.
Another problem with prior art chairs used in health care settings is the lack of seated comfort they provide. A major factor in this discomfort is the stationary aspect of the seating. Provision for some form of effortless motion prevents the concentration of pressure points at specific locations on the body which contact the chair and support weight.
This aspect of seating discomfort is caused by the inevitable concentration of body weight on specific portions of flesh. Under normal conditions of health and mobility, such pressure results in the desire to shift body weight and redistribute the pressure. However, in a weakened state and in a static chair, patients may be unable to do so. In the present invention, the natural motion of the chair provides relief.
Thus, an object of the present invention is to provide a chair in which slight rocking motion can be achieved, which provides an opportunity for exercise to the debilitated user; and which also allows the constant partial shifting and redistribution of body weight and helps the patient to dissipate institutionally and health-related anxieties by moving and rocking.
A problem with chairs of the prior art that accommodate a rocking motion by the user, is that the axis of rotation usually falls somewhere between the user's knees and pelvis, so that as the user rocks backward, there is a tendency for the knees to move upwardly, causing the feet to leave the floor and creating an excess of pressure on the underside of the thighs. In addition, there is a further tendency in the prior art chairs, as the user pushes downward on the fronts of armrests in order to lift himself upwardly, for the armrest fronts to rotate downwardly, opposite the direction in which the user is trying to push. Thus, another object of the present invention is to provide a chair with a rocking motion, the axis of which is located in front of the knees, and armrest fronts remain stable while the body rotates backward into the chair back; and one that has no tendency to rock forwardly when the user pushes down on the armrests to lift himself out of the chair.
Yet another problem with many prior art chairs used in health care settings in the manner in which impact is absorbed when a user drops into the seat. The most common means of absorbing impact shock is with heavy padding, which besides its potentially hygienic limitations, if effective, often permits the sitter to sink too low to be able to lift himself out of the chair easily, and creates both bulk and weight which limit an institutional staff's ability to move the chair and adequately perform necessary floor maintenance operations.
Such stuffing materials also often create fire hazards by the use of highly combustible materials which generate high smoke density and toxicity on combustion. A further object of the present invention is to provide a chair of minimum required bulk which permits minimal use of materials that would fuel a fire and the structure of which absorbs initial impact by the user.
The objects of the present invention are accomplished by providing a chair which is primarily though not exclusively intended for use by the weakened, partially disabled, or infirm user such as are typically found in hospitals, nursing homes, extended care facilities, and sickrooms, and which is directed primarily at the geriatric, orthopedic, rehabilitating, psychiatric, and maternity patient. It is particularly suited to these applications in that it is easy to enter and exit, provides with no moving parts a soothing slight rocking motion that increases rearwardly in order to shift and redistribute body weight without lifting the feet off the floor while maintaining stable arm fronts against which to push in exiting, minimizes skeletal shock upon sitting impact without padding of any kind which might potentially fuel a fire, and remains stable in all normal use.
The chair as described above consists of a tubular or barstock steel base frame, vertical leg components which support tubular or bar stock steel side frames which in turn support a seat and back member constructed of flexible material. The seat and back member may be formed of any suitable upholstery material, and the chair may be constructed so that the seat and back member may be removed for replacement purposes.
A major advantage of the chair is the placement and support of armrests. They are axially supported at their front end by a relatively rigid member so all downward force exerted at their front ends is resisted by the vertical legs of the chair acting as axial struts, thus providing the user a stable stratum against which to push for exiting the chair. Furthermore, these armrests extend well past the seat front, enabling the user to first pull himself far forward enough so that he is then pushing downwardly over the center of gravity of his feet enabling his leg muscles to perform a substantially higher proportion of the work than his arm and upper body muscles would otherwise have had to perform.
Another advantage is that portions of the seat and back that actually support the user's weight are a structurally efficient tensile sling, allowing use of a minimal amount of material in one thin layer. As shown in one embodiment, this sling consists of an open polyester mesh which provides both full ventilation to the user and complete washability. The amount of material required is so minimal, in fact, that it dries quickly without trapping water and contributes so little potential fuel that it is not subject to present flammability laws governing upholstered furniture.
Another advantage of the chair is the seated comfort it provides. The front-cantilevered side frames deflect rearwardly, leaning the user back into the chair with a slight but soothing rocking motion which further shifts concentration of the user's body weight to different tissue areas as his center of gravity shifts correspondingly back and forth. Since the point of fixing of the flexing cantilevered side frames is at their front end, the corresponding axis of rotation of side frames is just above and in front of the knees, which therefore remains relatively stable so there is no lifting off the floor of the user's feet.
Furthermore, the optimally placed lumbar support gives adequate support to the critical lumbar region, while the headrest can be adjusted up or down via hook and loop tape fasteners to correspond with the small of the neck within the range limited by its permanently sewn attachment straps. And as the user drops into the chair, the flexure of the side frames absorbs impact and prevents skeletal shock, for which heavy padding might otherwise be needed.
The elimination of the need for heavy padding thus produces a less bulky chair which can be moved more easily for cleaning, relocation, or even patient transport.
Yet another advantage of the chair is that the portions of the base that are on the floor are sized large enough so that the user's center of gravity always falls within those boundaries delineated by the base, thus precluding any instability in normal use.
Finally, the skeletal nature permitted by the chair's structure permits the attachment of a multitude of accessories to accommodate the treatments or functions not normally performed in a lounge chair.